Hi, Philipp


On 2016?12?16? 10:45, zhangfei wrote:

On 2016?12?15? 23:30, Ramiro Oliveira wrote:

quoted

Hi Andy and Zhangfei

On 12/15/2016 12:33 PM, Andy Shevchenko wrote:

quoted

On Thu, 2016-12-15 at 16:59 +0800, Zhangfei Gao wrote:

quoted

Some platforms like hi3660 need do reset first to allow accessing
registers

Patch itself looks good, but would be nice to have it tested.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

I tested the patch and it's working for the ARC architecture.

quoted

quoted

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
---
  drivers/i2c/busses/i2c-designware-core.h    |  1 +
  drivers/i2c/busses/i2c-designware-platdrv.c | 28
++++++++++++++++++++++++----
  2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-core.h

b/drivers/i2c/busses/i2c-designware-core.h
index 0d44d2a..94b14fa 100644

--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h

@@ -80,6 +80,7 @@ struct dw_i2c_dev {
      void __iomem        *base;
      struct completion    cmd_complete;
      struct clk        *clk;
+    struct reset_control    *rst;
      u32            (*get_clk_rate_khz) (struct

dw_i2c_dev *dev);
      struct dw_pci_controller *controller;
      int            cmd_err;

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c

b/drivers/i2c/busses/i2c-designware-platdrv.c
index 0b42a12..e9016ae 100644

--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c

@@ -38,6 +38,7 @@
  #include <linux/pm_runtime.h>
  #include <linux/property.h>
  #include <linux/io.h>
+#include <linux/reset.h>
  #include <linux/slab.h>
  #include <linux/acpi.h>
  #include <linux/platform_data/i2c-designware.h>

@@ -176,6 +177,14 @@ static int dw_i2c_plat_probe(struct

platform_device *pdev)
      dev->irq = irq;
      platform_set_drvdata(pdev, dev);
  +    dev->rst = devm_reset_control_get_optional(&pdev->dev, NULL);

devm_reset_control_get_optional() is deprecated as explained in 
linux/reset.h,
you should use devm_reset_control_get_optional_exclusive() or
devm_reset_control_get_optional_shared() instead, as applicable.

I submitted a similar patch earlier today and I made the same mistake.

Thanks Ramiro for the info
Will use devm_reset_control_get_optional_exclusive instead.
But should the interface be as simple as possible?

Thanks

Sorry, a bit confused.
Is that mean we should not use devm_reset_control_get_optional()
While driver should decide whether use 
devm_reset_control_get_optional_exclusive() or
devm_reset_control_get_optional_shared()
What if different platform has different requirement?

Looks the difference between _exclusive and _shared is refcount,
How about handle this inside, and not decided by interface?

Thanks